||It has been suggested that this article be merged into Group dynamics. (Discuss) Proposed since February 2013.|
Group behaviour (or group behavior) in sociology refers to the situations where people interact in large or small groups. The field of group dynamics deals with small groups that may reach consensus and act in a coordinated way. Groups of a large number of people in a given area may act simultaneously to achieve a goal that differs from what individuals would do acting alone (herd behaviour). A large group (a crowd or mob) is likely to show examples of group behaviour when people gathered in a given place and time act in a similar way—for example, joining a protest or march, participating in a fight or acting patriotically.
Special forms of large group behaviour are:
- crowd "hysteria"
- spectators - when a group of people gathered together on purpose to participate in an event like theatre play, cinema movie, football match, a concert, etc.
- public - exception to the rule that the group must occupy the same physical place. People watching same channel on television may react in the same way, as they are occupying the same type of place - in front of television - although they may physically be doing this all over the world.
Group behaviour differs from mass actions which refers to people behaving similarly on a more global scale (for example, shoppers in different shops), while group behaviour refers usually to people in one place. If the group behaviour is coordinated, then it is called group action.
Swarm intelligence is a special case of group behaviour, referring to the interaction between a group of agents in order to fulfil a given task. This type of group dynamics has received much attention by the soft computing community in the form of the particle swarm optimization family of algorithms.
Why do people join groups 
People join groups for a multitude of reasons. A major reason is that group membership often results in some form of need satisfaction on the part of the individual. Membership into a group can fulfill numerous needs, some which group members may not realize they are benefiting from:
- Companionship – groups provide members to simply be in the company of other people.
- Survival and security – From a historic or evolutionary perspective our ancestors would partake in group experiences for hunting and defence.
- Affiliation and status – membership into various groups can provide individuals with certain socials status' or security.
- Power and control– with group membership comes the opportunity for leadership roles; individuals who feel they need to exert their power and opinions over others can have such experiences within group settings.
- Achievement – groups have the capability to achieve more than individuals acting alone.
Organizations typically form groups in order to accomplish work related tasks; however, as a member of a work group you may unintentionally reap the numerous benefits independent of the original group construct.
Defining characteristics of groups 
Currently there is not a universal definition of what constitutes a group. Groups can have varying numbers of members, communication styles, and structures. Research has identified a few common requirements contributing to the recognition of individuals working in a collaborative environment to be considered a "group":
- Interdependence: In order for an individual of the collective to accomplish their part in the assigned task they depend, to some degree, on the outputs of other members of the collective.
- Social interaction: In order to accomplish the goal some form of verbal or nonverbal communication is required to take place amongst the members of the collective.
- Perception of a group: All members of the collective must agree they are, in fact, part of a group.
- Commonality of purpose: All the members of the collective come together to serve or attain a common goal.
- Favoritism: Members of the same group tend to be positively prejudiced toward other members and tend to discriminate in their favor.
Some researchers suggest additional characteristics need to be identified in order for a collective of individuals to be categorized as a group such as: working the same shifts, shared physical work locations, and reporting to the same manager. However the commonalities of the multiple definitions reviewed suggest that the definition of a group is based on the interdependence of people who come together to accomplish a common goal.
Types of groups 
- Production groups consist of front line employees who produce some tangible output. Autonomous production groups are self-directed or self-managing while semi-autonomous production groups typically have a dedicated supervisor who oversees all operations.
- Service groups consist of employees that work with customers on a repeated basis, such as airline teams, maintenance groups, sales groups, call centres, etc.
- Management groups consist of an executive or senior manager along with managers that report directly to him/her. Management groups are often able to organize themselves towards goals such as policy making, budgeting, staffing, and planning.
- Project groups are generally cross-function groups of individuals brought together for the duration of a specific, time-limited project. Project groups are usually disbanded once the project is complete.
- Action and performing groups are groups that typically consist of expert specialists who conduct complex, time-limited performance events. Examples include musical bands, military crews, surgery teams, rescue units or professional music groups.
- Advisory groups consist of employees that work outside of, but parallel with, production processes. Examples include quality circles, selection committees, or other advisory groups pulled together to make recommendations to an organization.
Group structure 
A group's structure is the internal framework that defines members' relations to one another over time. The most important elements of group structure are roles, norms, values, communication patterns, and status differentials.
A role can be defined as a tendency to behave, contribute and interrelate with others in a particular way. Roles may be assigned formally, but more often are defined through the process of role differentiation. Role differentiation is the degree to which different members of a group have specialized functions. Functional (task) roles are generally defined in relation to the tasks the team is expected to perform. Other types of roles are the socio-emotional role which helps maintain the social fabric of the group, the individual role and the leader role.
Group norms are the informal rules that groups adopt to regulate members' behaviour. Norms refer to what should be done and represent value judgments about appropriate behaviour in social situations. Although they are infrequently written down or even discussed, norms have powerful influence on group behaviour.
Group values are goals or ideas that serve as guiding principles for the group. Like norms, values may be communicated either explicitly or on an ad hoc basis. Values can serve as a rallying point for the team. However, some values (such as conformity) can also be dysfunction and lead to poor decisions by the team.
Communication patterns describe the flow of information within the group and they are typically described as either centralized or decentralized. With a centralized pattern, communications tend to flow from one source to all group members. Centralized communications allow consistent, standardization information but they may restrict the free flow of information. Decentralized communications allow information to be shared directly between members of the group. When decentralized, communications tend to flow more freely, but the delivery of information may not be as fast or accurate as with centralized communications. Another potential downside of decentralized communications is the sheer volume of information that can be generated, particularly with electronic media.
Status differentials are the relative differences in status among group members. Status can be determined by a variety of factors, including expertise, occupation, age, gender or ethnic origin. Status differentials may affect the relative amount of pay among group members and they may also affect the group's tolerance to violation of group norms (i.e. people with higher status are given more freedom to violate group norms).
Stages of group development 
Group development focuses on the somewhat unique way groups are formed and the manner in which they may change over time. There are a variety of development theories and some suggest that groups develop through a series of phases culminating in effective performance. The most common of these models is Tuckman's (1965) Stage Model. It breaks group development into the following five stages:
- Forming: As the group convenes, conflict is usually low to non-existent as everyone tries to determine their individual role and the personalities of fellow team members. This stage is often marked by agreeable neutrality while the group takes form and begins to navigate the unknown.
- Storming: Storming occurs after the group overcomes the sense of uncertainty and begins to actively explore roles and boundaries. Chaos, pronounced efforts to influence others, and instances of conflict and/or enthusiasm are common.
- Norming: Norming in groups indicate that norms and role ownership are emerging. Generally this means that conflict and chaos is decreasing or has ended.
- Performing: Originally noted as the final stage, performing occurs when the team completes their primary task(s).
- Adjourning: Tuckman (1977) refined the model to include a fifth stage to address how the group begins to disengage and move on to new tasks potentially beyond the team.
While Tuckman's (1965) model is useful in describing developmental processes, there are instances when groups do not strictly adhere to the exact sequence. Additionally, the storming stage may decrease but not fully dissipate and continue across other stages.
Intergroup dynamics and behaviour 
Intergroup behaviour, or the way groups interact with other groups, is best examined in terms of the frequency and interaction type the groups engage in. Thomas (1976) elaborated on this concept by noting the nature of intergroup interactions depends largely on the degree to which groups must interact in order to achieve their goals, and the degree of compatibility between the goals of different groups.
- Accommodation interaction is based on groups having similar goals and taking part in minimal to moderate mutual concession and cooperation to achieve them.
- Avoidance interaction is found between groups where there are different or conflicting goals and even minimal collaboration is not warranted. Both of these interactions are viewed as having no to low impact on successfully achieving each group's goals.
- Collaboration interaction is necessary when the goals of two groups are largely compatible and partnership is required for successful goal accomplishment.
- Competition interaction usually occurs when two groups must interact to meet specific goals that are vastly incompatible.
- Compromise interaction occurs when two groups have a moderate need to interact to meet specific goals which are moderately compatible. In this type of interaction, the two groups may work together on a semi-regular basis to ensure they are on track to meet the relevant aspects of their overlapping goals.
- Deindividuation is a phenomenon that occurs when individuals of a group become less aware of their values.
- Diffusion of responsibility is the tendency for group members to feel diminished responsibility for their actions when surrounded by others who are behaving in a similar manner.
- Intergroup behaviour is influenced by factors beyond interaction types. Examples of these include Interdependence, Organizational Culture, Past History, and Organizational Social Networks.
- Interdependence is the degree to which group depend on each other and is determined by the type of group tasks (i.e., simple versus complex), organization structure, and the organizational authority system). Interdependence may occur in one of three common forms:
- Pooled interdependence: The combined efforts of largely separate groups positively contribute to the organization.
- Sequential interdependence: The effort or output of one group is used as the input for another group.
- Reciprocal interdependence: A series of mutual exchanges between groups, requiring a high degree of continuous interactions.
- Organizational culture, its shared norms, values, and power structure, will often dictate the frequency and degree to which intergroup interactions and collaborations occur.
- Past history with intergroup relationships also impact interdependence behaviour. The influence of this factor is directly connected to the past interaction experience between groups. Whether the interaction was positive or negative, new group members may be influenced in the direction of the group's previous experience.
- Social networks in organizations are another vital factor when considering intergroup behaviour. Cordial individual group member interaction is believed to greatly impact the quality of intergroup relationships.
Intergroup conflict 
Intergroup conflict may be caused by competition for resources, goal incompatibility, time incompatibility, and contentious influence tactics. There are activities that organizations can participate in to reduce or prevent competition between groups.
- Resources: Resources (e.g., budgets, personnel, physical space) are generally limited within organizations so that competition for resources between groups is often unavoidable.
- Goal Incompatibility: Goal incompatibility occurs when the goals of two or more groups are in direct opposition such that one group will achieve its goal while the other group(s) will be unable to meet the goal. Goal incompatibility may be distinguished between real goal incompatibility and perceived goal incompatibility.
- Time Incompatibility: Work groups perform different tasks, have different goals, and interact with different customers such that groups will have different time frames or deadlines in which they operate.
- Contentious Influence Tactics: Contentious influence tactics (e.g., threats, demands, and other negative behaviours) may be used to attempt to influence others from another group creating cycles of retaliation and influencing the opinions of those within their own group (e.g., creating bad reputations).
Consequences of intergroup conflict 
Effects related to conflict between groups may be either negative or positive.
- Group members' perceptions of one another change in a negative manner where a distinction is made between "in-group" and "out-group".
- Members of groups in conflict develop an "us versus them" mentality and view members of the other group as fundamentally different from themselves but similar to each other.
- Group members become more cohesive to compete against a "common enemy".
- Quality of intergroup interactions (e.g., communication) may decline among groups in conflict, which in turn may decrease the quality of work.
- Negative perceptions of the other group may be transferred to incoming group members.
- Conflict may create discrepancies between the goals of the group and the goals of the organization.
Improving the quality of intergroup relations 
Superordinate goals are goals that are approved by all groups and that may require the groups to interact in a cooperative manner to achieve the goals (e.g., produce a product, prepare a report, and complete a service to customers). Superordinate goals may also be used to create a "common enemy" that increases the cohesion among group members to defeat the enemy.
Negotiation may facilitate communication of issues causing conflict between groups so that groups can form a resolution that is suitable to members within both groups. "Principled negotiation" refers to one style of negotiation so that members attempt to problem-solve until a resolution between groups is reached rather than focusing on which their individual positions. (Fischer and Ury, 1981)
Member exchanges allow group members to exchange roles with those of the other group members. These exchanges are intended to provide a new perspective.
Intergroup Team Development may be used to improve relations for members within the same group or between groups. One intervention developed by Blake, Shephard, and Mouton (1964) has members of both groups generate one list about how the group perceives the other group and one list that describes how they think the other group will describe them; the lists are then shared with both groups to reduce misperceptions.
Reducing the need for intergroup interaction may be necessary for work groups that cannot work well together. A "coordinating group" may be used as an intermediary between groups so that each group would communicate through the "coordinating group". Organizations may create slack resources by adding additional inventory so that groups do not have to interact as frequently. Organizations may also reduce task interdependence between those groups that function under different time frames and deadlines (i.e., physically separate the groups).
The resource allocation process should be fair so that all groups have access to the process and political considerations between groups are minimized. Organizations should first reexamine the process to determine that groups have the resources needed to be effective.
See also 
- Bandwagon effect
- Behavioural sink
- Belbin Team Inventory
- Collective consciousness
- Collective effervescence
- Collective hysteria
- Collective intelligence
- Collective narcissism
- Crowd psychology
- Group conflict
- Herd behaviour
- Judge–advisor system
- Keeping up with the Joneses
- Mob rule (ochlocracy)
- Moral panic
- Peer pressure
- Social anthropology
- Social behaviour
- Social comparison theory
- Spiral of silence
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